1. Field of the Invention
The present invention relates to an uninterruptible power supply (UPS), and more particularly to a UPS with a power isolation circuit loop.
2. Description of the Related Art
Conventional UPSs in the market are connected to electric/electronic appliances and mainly serve to supply power during power outage. Certain UPSs also provide functions for irregular power prevention and noise immunity to protect electric/electronic equipment, especially for precision instruments requiring higher power quality. By and large, UPS is not major equipment to users unless users have a demand for higher power quality.
Taiwan Power Company announces that the average power outage time per power consumer in the science parks island-wide is 1.2 minute (about 72 seconds) in 2010. Such power supply performance can be ranked high in terms of power supply quality because those power consumers in the science parks are densely concentrate and mostly pertain to electronic, semiconductor, communication and photonics industries, which usually suffer heavy loss upon power outage.
Besides the production lines of manufacturers in the science parks, regular users also require UPS in their daily life. The commonly used UPSs are UPSs with replaceable batteries, and the circuit design of the UPSs is to design a circuit on a battery side as an isolation circuit for effectively isolating power coming from electric/electronic appliances connected to the UPSs, thereby protecting power users from the risk of high-voltage shock during battery replacement. However, additional isolated power source, optical coupler, isolated detection circuit, and the like are needed between a primary-side circuit and a secondary-side circuit, and the element cost and the challenge to internal space utilization are relatively higher. In addition, the disadvantages in terms of complicated circuits, more isolated elements, high UPS cost, and larger size of circuit board inside the UPSs also exist.